The quality and realism of the sound produced by the sound systems in movie theaters continues to improve. The realism is produced by using a technique commonly referred to as surround sound wherein multiple sound tracks are recorded and the sound from each of the tracks are played back in speakers that are located in different directions relative to the audience. Currently, many feature films are recorded using seven sound tracks. The seven sound tracks typically include a left surround sound track and a right surround sound track. The left surround sound track is played back through one or more speakers that are behind and to the left of the audience. The right surround sound track is played back through one or more speakers that are behind and to the right of the audience. The remaining five tracks are played back through speakers that are at various angles in front of the audience. Some films have an eighth track that is played back through a subwoofer. The sound produced by typical home stereo systems does not approach the sound realism provided by surround sound in movie theaters. Most home stereo systems reproduce stereo sound in two speakers that are typically located in front and to each side of the listener. More sophisticated home stereos are able to reproduce the surround channels. The most sophisticated home stereo systems have eight or more speakers and can reproduce all eight sound tracks. However, such home stereo systems are relatively expensive.
In addition, surround sound signals generated for movie theater sound systems and home systems do not readily adapt to head phones as head phones isolate the sounds going to each ear. This is quite different from a movie theater surround sound system, for example, which provides sounds coming from a number of speakers which are detected by both ears of the listener.
The sound used in computer applications has also improved. In the past, computer programs did little more than generate beeps with varying durations and frequencies. Currently, some computer programs are able to generate stereo sound with a sound quality that rivals audio CDs. Some sound adapters allow users to connect sound cards to home stereo equipment so that the sound generated by computer programs (especially computer games) may be reproduced with minimal distortion. In spite of such improvements, the sound produced by computer applications does not approach the sound realism provided in movie theaters.